Electrical connecter



March 1... P. NELSON ELECTRICAL coNNEc'rER Filed Nov. 25; 1952 JNVENTOR. Louis RJVeZs'On Patented Mar. 6, 1934 UNITED STATES PATENT OFFICE;

1 49,973 EIEGTBIC CONNECTEB Louis 1. Nelson, Philadelphia, Pa.

Application November 25, 1932, Serial No. 644,318

Claims. (oi. 173-343) This invention relates'gto conneoters such as are customarily employed 'for connecting extension cords with ordinary house lighting circuits and the like so as to conduct the current from I the circuit to an appliance such as a lamp, electric iron, vacuum cleaner, or other movable electrical device. Connecters adapted for this purpose usually comprise two separable parts one of which is attached to the end of the cord and the other designed for reception in a lamp socket or the like, the two parts being provided with interengaging elements through which the requisite electric uconnection is made. It has been found, however, that connecters of this character are more or less unsatisfactory under certain conditions of use since a sufficient pull on the cord. either accidental or otherwise, is effective to separate the connecter parts, thus interrupting the circuit to the appliance, and it is the primary Q0 purpose of my invention to obviate this objection by the provision of means whereby the separable elements of the connecter can, after assembly, be readily yet positively locked together against separation yet as readily unlocked when it is desired to break the connection.

The principal object of the invention, therefore, is the provision of an improved connecter comprising separable elements and means for positively yet releasably locking them in assembled relation.

A further object of the invention is the provision in a connecter of the character aforesaid of locking means which, while eminently suitable for the performance'of their intended function, are of simple design and construction and not liable to get out of order under the conditions of use to which connecters of the sort to'which my invention relates are necessarily subjected;

which do' not greatly increase the cost of man- 4c ufacture of the connecter as a whole, and which in no wise interfere with the assembly or separation of the connecter parts but which can be readily operated to lock said parts together after assembly and as readily released to permit their separation when desired.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or will be understood from the following description in which reference will be had to the accompanying drawing.

In the said drawing Fig. 1 is a side elevation partly broken away into section of one embodiment of my invention, showing the plug and socket vmembers of the connecter in assembled relation; Fig. 2 is a front'elevation thereof in which the lines 1-1 indicate the planes of section in Fig. 1; Fig. 3 is a rear elevation of the plug member; Fig. 4 is a side elevation thereof partly broken away into section with the locking. ring removed; Fig. 5 is a front elevation of the socket member, and Fig. 6 a side elevation thereof; Fig. 7 is a rear elevation of the locking ring removed from the plug member shown in Fig. 4, and Fig. 8 is a side elevation thereof partly broken away into section. In the several fig ures, like characters are used to designate the same parts.

While I have shown in the drawing a connecter adapted for reception in an ordinary lamp receptacle and therefore having a standard threaded plug projecting rearwardly from the socket member, it will be understood that my invention is also adapted for use in wall receptacles and the like in which the socket member is built into the wall or floor with its outer face lying flush therewith with suitable concealed wiring secured to the contacts by binding posts in the ordinary way, sockets of this type being particularly useful for interconnection with vacuum cleaner plugs, floor lamp plugs, and the like. I

In the embodiment shown in-the drawing, however, the socket member A of the connecter comprises a dielectric body 1 adapted for reception in a lamp socket of usual form and surrounded by a threaded brass or other suitably conductive sleeve 2 serving as one contact member, while an axial projection 3 desirably formed of brass or the like and adapted to contact a suitable corresponding member in the bottom of the lamp receptacle in the usual way, serves as the other, the contacts 0 2 and 3 being respectively connected internally of i the socket with spring contacts 4, 5 disposed within slots 6, '7 which receive the projecting contact prongs of the plug member B. The body 1 is provided with a radial flange 8 having its outer surface substantially flush with the end of the body and in this flange are formed diametrically opposed holes 9 and curved or arcuate slots 10 respectively extending for a short distance clockwise therefrom as shown in Fig. 5.

Like the socket member, the plug member B is desirably formed principally of dielectric material such as bakelite, hard rubber or the like and comprises a body 15 having a radial flange 16, approximating in diameter the flange 8 of the socket member; disposed adjacent its inner end and, preferably, an axially extending bell-shaped annular guard 17 at its outer end communicating with a central bore 18 through which the extension 'cord (not shown) extends, so that the 1 conductors in the latter may be respectively interconnected by means of binding posts 19, 20 to the projecting contact prongs 21, 22. The latter are suitably located for engagement with the contacts 4, 5 upon their projection into the slots 6, 7 in the socket member and may be substantially similar to corresponding parts in ordinary pushand-pull connecters of well known types. The

flange 16 of the plug member is provided with a pair of curved or arcuate closed slots 24 substantially diametrically opposed and adapted to receive the shanks of a pair of headed pins 25 carried by a locking ring 26 preferably formed of dielectric material, which, in the assembled plug, is rotatably seated on the body and I 8, 16, while the pin heads are of suflicient diameter to prevent them from passing through the slots 24 in the latter when the ring and pins are assembled with the plug B.

Frominspection of the drawing, it will be apparent that the prongs 21, 22 project considerably farther from the flange 18 than do the pins 25, and it therefore results that when the plug B is moved toward the socket A when the connecter is being assembled, the prongs enter the slots 6, '1 in the socket before the heads reach the socket flange 8 so that during the further movement of the plug requisite to bring it to fully assembled position with respect to the socket, the pins can pass through the holes 9 in the flange 8 until their heads project beyond the opposite face of the flange when the plug has been pushed in as far as it will go. In order to properly enter the heads of the pins in the holes, it may sometimes be necessary to turn the locking ring slightly in one direction or the other while the plug is being pushed home, but once it is fully seated with respect to the socket, the locking ring may then be turned in a clockwise direction when viewed from the front so as to move the shanks oi the pins into the arcuate slots 10 and thus bring the heads of the pins into substantial engagement with the rear face of the flange 8 in which position they overlap the sides oi .the slots 10. Ihe plug member is thereby securely locked to the socket member and separation of these parts as a result oi an inadvertent pull on the cord extending from the plug member is prevented, although they may be readily unlocked by a reverse movement of the ring to align the heads of the pins with the holes preparatory to withdrawing the plug axially from the socket, the bell-shaped extension 17 providinga convenient grip for use in removing the plug without the necessity for pulling on the extension cord.

The dielectric portions of the connecter may readily be made by suitably molding or otherwise forming bakellte, hard rubber, or any other de-,

sired insulating material, while the electrically conductive parts are substantially similar to those now employed in ordinary push-and-pull type connecters; consequently, my improved locking connecter may be manufactured at a cost not substantially greater than that of ordinary con necters of this type, not provided with any looking means, which are now on the market.

Although I have herein described one embodiment of my invention with considerable particularity, I wish it to be understood that I do-not. thereby intend to limit or confine myself thereto in any way, for while the form of connecter herein shown and described is admirably adapted to fulfill the objects and purposes of the invention, the latter is susceptible oi! embodiment in various other forms and modifications without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent 0! the United States:

1. An electrical connecteroi the class described comprising a socket member having an outwardly directed flange provided with 'arcuate slots and holes 01' greater diameter than the width 01' the 05 slots communicating therewith, a plug member having contact prongs adapted for reception in the socket member and an outwardly directed flange, a locking ring carried by and rotatable with respect to the plug member, headed pins fixed to said ring, projecting through the plug flange and engageable in the slots in the socket flange by rotation of the ring relatively to the, plug member after .said prongs have been re-\ ceived in the socket member and the heads of the pins passed through the holes in its flange.

2. An electrical connecter of the class described comprising cooperative plug and socket members each of which is provided with an outwardly directed flange having arcu'ate -slots in substantial 11;) alignment when the members are in cooperative relation, a locking ring rotatable on the plug member, and means carried by the ring, projecting through the slots in the plug flange and adapted to extend through the slots in the socket flange when the plug and socket members are in said relation and the ring rotated to a predetermined position. i

3. An electrical connecter of the class described comprising cooperative plug and socket members each of which is provided with an outwardly directed flange having arcuate slots in substantial alignment when the members are in cooperative relation, a locking ring rotatable on the plug member, and means comprising headed'pins carried by the looking ring and respectively adapted to extend through the slots in both flanges with their heads projecting beyond the socket flange when the members are in said relation and the ring turned to a predetermined position 30 4. An electrical connecter of the class described comprising a socket member having prong receiving slots and a radial flange provided with holes and with arcuate slotscommunicating therewith of less width than the diameter or the holes, a plug member having longitudinally extending contact prongs adapted to enter the prong receiving slots in the socket and a radial flange provided with .arcuate slots, a locking ring disposed adjacent said flange and rotatable axial- 1y about the plug member, headed pins extending 'i'rom said ring through the slots in said flange sockets oi the socket member while the plug is being brought to assembled relation therewith,

whereby after such relation is obtained the pins can be caused to enter the slots in the socket flange with their heads in overlapping relation with the sides thereof by limited revolution of the ring on the plug member to thereby lock the plug member to the socket member against longitudinal separation.

5. In an electrical connecter, a plug member 

